Soap cream



July 14, 1936., R H FERGUSON 2,047,320

SOAP CREAM Filed June 14, 1933 INVENTOR.

Patented July 14, 1936 UNITED STATES .PATENT OFFICE SOAP CREAMApplication June 14, 1933, Serial No. 675,790

8 Claims.

This invention relates to improvements in soap creams, suitable for useas shaving creams, or for other purposes.

Its object is to provide an improved soap cream which, besides yieldinga copious and lasting lather, and having a good texture and otherproperties required in a good shaving cream, will retain its good creamyconsistency over a wide range of temperatures, including high summertemperatures, without becoming stiff and gummy.

Pure soap creams suitable for use as shaving creams have always in thepast had the objectionable feature of becoming thick and gummy at summertemperatures if they are made so as to have the desired creamy textureat ordinary temperatures of approximately 60-80 F. A good shaving creamshould have the following characteristic. It must have a good creamytexture, without being so thin as to run out of the tube easily, nor sothick as to interfere with its use at ordinary temperatures; it mustspread easily on the shaving brush or on the skin, must dissolvereadily, form a copious lather of good lasting qualities, and contain nomaterial harmful or irritating to the skin. In making a soap cream tomeet these requirements, it has usually been found best to use mainly asolid fat or fats such as tallow or commercial stearic acid. in order toobtain a soap which gives a lather with good lasting qualities, and withit a relatively small percentage of oil of the coconut type to improvethe solubility and quick lathering property of the soap product. Amixture of potash and soda is commonly used to saponify the fattyingredients because it has been found that such a mixture gives a creamof better solubility than soda alone, and a better texture than eitheralkali alone. It is found that creams having a real soap content ofapproximately 40-45%, with the balance consisting mainly of Water, havea desirable texture at ordinary temperatures. Regardless, however, ofthe kind of fat heretofore used, or the kind or relative proportions ofalkali, or the percentage of real soap in the finished neutral soapcream, it has invariably been found that if the texture is suitable foruse at average temperatures, such as F., for example, it will invariablybe much.

too stiff at temperatures higher than approximately F. The cream changesat these higher temperatures to a relatively stiff gummy mass which isdifficult to squeeze out of thetube, tends to roll off the shavingbrush, does not spread easily on the skin, and is slow in dissolving.Attempts have been made to overcome these defects in various ways, suchas by adding electrolytes, or excess free fatty acid, or neutral fat,but results are only partially satisfactory, and in any event myprocedure atcomplishes the desired result in improving the texture, atwarm temperatures, regardless of the addition of other ingredients.

My invention consists in the discovery that hydrogenated oils or fats(as described below) when used as the predominating fat constituent insoap creams, not only yield creams of good texture at ordinarytemperatures, but impart to them the desirable and valuable property ofretaining a creamy texture even at the highest summer temperatureswithout becoming stiff or gummy; that is, if made in accordance withordinary practice, so as to have a desirable texture at temperatures of60-80 for example, they will retain this texture even when used attemperatures of F., or even higher in many cases. They will also retaina desirable creamy texture at temperatures as low at 40 F. Hence, theyare always in a good creamy condition'at any temperature at which theyare likely to be used, either winter or summer.

Most of the common vegetable or animal oils or fats, except those'of thecoconut oil group, may be used after hydrogenating, such as, forexample, cottonseed, peanut, soya bean, sesame, corn, sunflower, olive,linseed, rape, etc., among the vegetable oils; tallow, lard, oleo oil,tallow oil, etc., among the animal fats and oils; the hydrogenationshould'preferably be carried to an iodine value of 10 or lower.

The essential point is to hydrogenate a suitable oil to such a pointthat the product when saponified will produce soap crystals of unusuallyhigh melting range. This result is apparently due to the presence in thehydrogenated product of an unusually high percentage ofsaturated fattyacids like stearic acid, having 18 carbon atoms per molecule, or higherhomologues, and a minimum of acids of lower molecular weight thanpalmitic. I have found that the fatty acids in the hydrogenated oils orfats which are suitable for my purpose always contain at least 45% ofstearic acid and/or higher homologues, which percentage is eonsiderablyhigher than is found in the fatty acids from any natural fat or oil, orany commercial product of same. Tallow, for example, ordinarily containsonly about 15% of such fatty acids; palm oil 9%. Softer fats and naturalliquid oils in general contain much less. Even commercial stearic acidcontains only about 40% of actual stearic acid, with practically nohigher homologues, most of the remainder being palmitic acid; rarelydoes the percentage exceed' may also be used, but make pure neutral soapcreams of slower solubility although the texture at high temperatures issatisfactory.

Oils, fats, or fatty acids suitable for this purpose may be most easilyselected by the following test: First hydrogenate until the iodine valueis reduced to 10 or lower. Then convert 100 grams of the oil (or 95grams of fatty acids) to potassium soap by boiling with caustic potashsolution according to well known soap making procedure, taking care toavoid an excess of caustic potash, and adding sufficient water to give atotal weight of 240 grams when finished. The resulting soap cream(containing the liberated glycerine if neutral stock was used), willcontain about 40% fatty acids or about 45% real soap. Transfer a portionto a tight bottle, cool to F., and hold at about this temperature fortwelve hours or longer; then place in an oven at F. for two hours,retaining another portion of the orignal soap cream at about 70 F. forcomparison. If the potash soap thus made retains its opaque and creamyform and does not become gummy at 95 F., the hydrogenated oil or fatfrom which it was made will be suitable for use in making my improvedproduct.

Formula A (below) shows a typical formula for making a pure shavingcream of the prior art, although small percentages of other ingredients,such as glycerine, salt, perfume, etc., are often added. This cream willmake a good and lasting lather, and is of proper texture at ordinarytemperatures, but changes to the usual gummy condition at temperaturesof approximately 90 F.; it is difllcult to keep it on the shaving brushor to spread it on the skin when used at these higher temperatures.

Formula B is the same except that the fatty acids from hydrogenatedcottonseed oil (hydrogenated to an iodine value of less than 10) havebeen substituted for the commercial stearic acid of formula A. Thiscream shows practically identical texture at ordinary temperatures asdoes that from Formula A, but when used at temperatures above 90 F. itdiffers markedly in that it retains almost unchanged its creamy textureand can be spread on the brush or spread on the skin without difficulty,even at temperatures as high as F.

Fatty acids from hydrogenated cottonseed Coconut oil 4.8 Caustic potash,422 B 17.6 Caustic soda, 422 B 2.9 Water 39.5

Both of these formulas will produce good soap creams, by ordinary soapmaking procedure, that will contain about 45% real soap, will be nearlyfree from unsaponified fatty material, and will contain no free alkalior other irritating ingredient.

Reference to the drawing, which is made from actual photographs, willshow the difference in texture clearly.

The Figures 1 to 4 represent two samples of shaving cream made fromFormulas A and B, respectively, as expelled from theusual form ofcollapsible tube at temperatures of 40 F., 70 F., 90 F., and 100 F., asindicated.

In all these cases, the creams were expelled from the tubessimultaneously and in equal amounts, and the photographs taken exactlyone minute after the creams were expelled. It will be noted that attemperatures of 40 and 70 F., both samples were of such a soft creamytexture that they readily flattened out to a considerable extent, asshould be expected. At 90 and 100 F., however, A, the priorart product,is so stifi and gummy that it will not flatten out, but B, the productof this invention, has flattened out, showing that its consistency evenat the highest of these temperatures is practically the same as at lowertemperatures, evenas low as 40 F. It retains a good creamy consistencyat all temperatures from 40 F.-or lower up to temperatures considerablyabove 100 F.

The difference between these two creams is due to no other factor thanthe use of the hydrogenated oil (or fatty acids), and the difference inconsistency and utility at warm temperatures is very striking. The samekind of improvement is found in all cases where hydrogenated oil or fatof the class described, and producing a soap of unusually high meltingrange, is substituted for ordinary commercial fats and oils in shavingcreams. It is, of course, understood that in making the soap cream it isimmaterial whether the hydrogenated oil or fat itself is used, or thefatty acids from same; the fatty acids may even be hydrogenateddirectly. The resulting soap cream will be practically identical,although when a neutral oil or fat is used, there will be a small amountof glycerine liberated by the saponiflcation, instead of the water whichis liberated by saponiflcation of fatty acids, but this has nopronounced effect on the texture of the product.

While I have used commercial stearic acid in the example, this is merelybecause it has been found to be one of the best materials available formaking soap creams in the prior art, of good texture, latheringproperties and consistency at moderately warm temperatures, but itshould be understood thatthis is used merely as one example of fattysubstances well known to make relatively good soap creams. The samesuperiority of my soap creams would be at least equally obvious if anyother ordinary fatty material had been chosen in place of stearic acidin the example.

The explanation of this improved and rather unexpected action obtainedby the use of hydrogenated oils producing soaps of unusually highmelting point as a dominant constituent in the fat formula is probablyas follows: Soap creams normally consist at ordinary temperatures of amass of fine crystals of soap surrounded by a quantity of soap solution.These crystals are readily apparent when the creams are examined under amicroscope. The use of both soda and potash in making the soap gives thecream this advantage, that the soda and potash soaps crystallize indifferent forms which interlace with each other and prevent forming asolid compact 75 erent soap phase. This change is from a mixture ofcrystals and solution, not to a liquid solution, but to the phasedescribed in modern text books as middle soap, which is the gummycondition previously referred to, and then it loses its creamyconsistency.

Attempts to make a cream which will stand higher temperatures withoutbecoming gummy by using fats which make soaps of lower melting range orby increasing the water content of the mass or other apparently simplemeans, have always failed because in all such cases the result is tomake the cream too soft for use at ordinary temperatures, and in anyevent, it will still change to the gummy phase at moderately warmtemperatures.

A temperature range of about 2' to 6 F. is usually necessary to completethe change to the gummy condition; that is, if a given soap cream beginsto change to the middle soap phase at 87 F., for example, the changewill be completed by the time the temperature reaches about 91 andlittle if any further change takes place on further heating within anyordinary range of temperature. With ordinary pure neutral soap creams,this change is substantially completed at temperatures varying fromabout to F. Soap creams can be made by my improved procedure, however,which will remain in the phase composed of crystals surrounded by soapsolution until heated to temperatures of about 100 F., or even to 105 F.before changing to the middle soap or gummy phase, and thus have adesirable creamy texture over a wide range of temperature covering allthe temperatures commonly met with in winter and summer conditions,including high summer temperatures at which ordinary soap creams assumethe gummy state.

The proportion of hydrogenated oil in the total fat mixture necessary tokeep the transition point to the middle soap phase above anypredetermined point such as F., for example, varies considerablyaccording to circumstances and can best be determined by experiment ineach case, but in general at least 50% of the fat in the formula shouldconsist of hydrogenated oil as described. If the balance of the formulaconsists of fat or fatty acids yielding soap of relatively high meltingpoint, such as commercial stearic acid, then the use of as little as 50%of hydrogenated oil will be found to give greatly improved results, buthigher percentages will cause the product to stand a still highertemperature before changing to the gummy condition. If, however, thebalance of the fat consists of fats or oils yielding soap of relativelylow melting range, then it is necessary to use in all cases considerablyhigher "percentages of hydrogenated oil in the mixture. I find that afat formula consisting of about 85 to 90 parts of a suitablehydrogenated oil with 10 to 15 parts coconut oil (or their equivalentfatty acids) yields a soap cream of good properties which withstands thehighest summer temperatures very satisfactorily, when made withsubstantially the relative proportions of potash and soda and undersubstantially the preferred conditions shown in this specification andin the example.

It should be understood that while I have mentioned the use of thesesoap creams for shaving purposes, this is by no means their only use,but 5 they are well suited for many other uses, such as for generaltoilet use and for use in soap dispensers, etc.

It should also be understood that the terms hydrogenated oil andhydrogenated fat as 10 used herein are essentially synonymous, and theterm "hydrogenated oil as used in theclaims therefore covers either afat or a fatty oil which has been hydrogenated, as described, or thefatty acids from same. 15

Having thus described my invention, what I claim as new and desire tosecure by Letters Pat 1. A soap cream having a creamy consistencythroughout the range of temperatures from 40 F. to F. which whenexamined under a microscope at any temperature in this range is found tocomprise crystals of soap in a mother liquor, said soap creamcharacterised in that of the real soap content thereof more than halfthereof is,

the real soap content thereof more than half' thereof is made from oilssuitable for soap making other than those of the coconut classhydrogenated so as to contain more than forty-five per. cent ofsaturated fatty acids having at least eighteen carbon atoms permolecule.

3. A soap cream having a creamy consistency throughout the range oftemperatures from 40 F. to 100 F. which when examined under a microscopeat any temperature in this range is found to comprise crystals of soapin a mother liquor, said soap cream characterized in that more than halfof the fatty acids contained in same are hydrogenated saturated fattyacids suitable for soap making having at least eighteen carbon atoms permolecule.

4. A soap cream having a creamy consistency throughout the range oftemperatures from 40 F. to 100 F. which when examined under a microscopeat any temperature in this range is found to comprise crystals of soapin a mother liquor, in which cream the creamy consistency attemperatures from 90 F. to 100 F. is due to the use of soap made fromoils suitable for soap making other than those of the coconut classhydrogenated to an iodine value of not over 10, 0

- at temperatures from 90 F. to 100 F. is due to the use of soap madefrom oils suitable for soap 7 making other than those: of the, coconutclass hydrogenated so as to contain more than fortyfive per cent ofsaturated fatty acids having at least eighteen carbon atoms permolecule. 7 6. A soap cream having a creamy consistency 75 throughoutthe range of temperatures from 40 F. to 100? F. which when examinedunder a microscope at any temperature in this range is found to comprisecrystals of soap in a mother per molecule.

that of the real soap content thereof more than half thereof is madefrom oils suitable for soap making other than those of the coconutclass. hydrogenated to an iodine value of not over 10.

8. A soap cream having a creamy consistency throughout the range oftemperatures from 40 F. to 100 F., said soap cream characterized in thatmore than 45 per cent of the fatty acids contained in same arehydrogenated saturated fatty acids suitable for soap making having at 10least eighteen carbon atoms per molecule.

RALPH H. FERGUSON.

